package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        Long userId = UserHolder.getUser().getId();
        // 1.判断关注或取关
        if (isFollow) {
            // 2.关注，新增数据
            Follow follow = new Follow();
            follow.setFollowUserId(followUserId);
            follow.setUserId(userId);
            boolean isSave = this.save(follow);
            if (!isSave) {
                return Result.fail("保存关注数据失败");
            }
            stringRedisTemplate.opsForSet().add(RedisConstants.FOLLOW_USER_KEY + userId, followUserId.toString());
        } else {
            // 3.取关，删除数据
            boolean isRemove = this.remove(new LambdaQueryWrapper<Follow>()
                    .eq(Follow::getUserId, userId)
                    .eq(Follow::getFollowUserId, followUserId));
            if (!isRemove) {
                return Result.fail("删除关注数据失败");
            }
            stringRedisTemplate.opsForSet().remove(RedisConstants.FOLLOW_USER_KEY + userId, followUserId.toString());
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count > 0);
    }

    @Override
    public Result followCommons(Long id) {
        // 获取当前用户id
        Long userId = UserHolder.getUser().getId();
        if (userId == null) {
            return Result.fail("当前没有用户");
        }
        Set<String> ids = stringRedisTemplate.opsForSet().intersect(RedisConstants.FOLLOW_USER_KEY + userId, RedisConstants.FOLLOW_USER_KEY + id);
        if (ids == null || ids.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        List<Long> idList = ids.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> userDTOS = userService.listByIds(idList)
                                            .stream()
                                            .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                                            .collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
